The accident came less than two days after a coach crash near London's Heathrow Airport left two dead and dozens injured.

The skiers - a mixed party made up of families - were at the end of their holiday and en route to Grenoble airport to fly home when the accident happened between La Grave and Mizoens.

One Gendarmerie officer said that the the coach had skidded on ice, colliding with barriers on both sides of the road but remaining upright.

The seriously injured British man, who has not been named, was thrown through the front windscreen of the coach, the officer said.

He was quickly taken to hospital in Grenoble. No other vehicles were thought to be involved in the crash, police said.

The party had been travelling with SkiPlan, a Brighton-based specialist tour operator handling trips to ski schools, operating in France, Austria, Italy, Switzerland, the US and Canada.

Director Patricia Couchman said: "A party travelling with SkiPlan were involved in an accident when the coach transferring the group from resort to Grenoble Airport hit black ice and collided with the barrier.

"The accident happened at approximately 5.30am local time this morning. Our best information at the moment is one adult is in hospital with serious injuries.

"Two other adults were treated in hospital for suspected injuries but have been cleared by the hospital and are on their way back to the airport to travel home with the rest of the group.

"All other party members were fit to travel home."

She said that they had been transferred to another coach and taken to Grenoble Airport where their original flight had been delayed to accommodate them.

The road to Grenoble follows the Romanche valley, passing some of France's best known skiing resorts, including Les Deux Alpes and Alpe d'Huez. Nearby, the road crosses the Col du Lautaret at 6,752ft (2,058m).

In July 1997, three children from Bolton, Lancashire, on a school trip to France, were killed when their coach left a narrow mountain road in the Alps.

Their vehicle plunged into a ravine near Albertville, north-west of Grenoble.